- [Narrator] Indiana has the best fireflies also known as lightning bugs.

They're actually beetles, of course.

When I moved to California, I made my girlfriend a fake jar of them every year to remind her of the Midwest unaware how much of a romance language I was really using.

Let's travel Across Indiana to learn more.

First stop, a firefly expert with the Indianapolis Zoo.

- Fireflies produce bio luminescence so they produce light in darkness with their own bodies.

And that's something that very few animals do in a terrestrial environment.

Their mating song is sung in light.

All of that has quite a lot of undertones of passion.

It's something different and that has something sort of magical in it.

- [Narrator]} The fireflies glow began as a way to alert predators telling them, "Hey, if you eat me you'll regret it."

But as evolution evolved, the warning sign took on a new use.

Males and females started using their glow to talk to each other, let them know they are available.

Are there any type of flashes that are more popular with the ladies?

- That's a good... Well, I don't know about human ladies.

With female fireflies, some of the most popular flashes seem to be the one that are very fast.

So a lot of the speed of flashing and number of flashes seem to indicate good quality.

A male firefly is the one that keeps flashing and keeps going 'cause it's very rare for a female firefly to pick the first male she will see flashing.

It's usually about seeing a male, persistence, persistence and being in the right place at the right time.

- [Narrator] Here's how to spot the three most common fireflies you might see in Indiana.

- One of the first flashing fireflies in Indiana is the spring treetop firefly.

And their flash pattern is fairly simple.

They have a lot of rhythm 'cause a firefly with no rhythm is a dead firefly.

But their pattern is a flash.

One, two, flash.

One, two flash.

Probably the most common fireflies in Indiana even here in Indianapolis, and it's called the Big Dipper 'cause it has a flight pattern mixed with a light pattern which does a wong then silence, silence, wong.

And it does that a few times.

And because they have a low flight, they're very easy to catch and they also fly fairly low so a child can get them.

As that firefly goes, the wiggle dancer.

It's usually described as a flicker or a strong flicker, which is something like (mouth buzzing) and then nothing.

(mouth buzzing) The Say's firefly or the state insect will actually glow orange because it looks like a flicker of a candle, so it's very yellow orangy like that.

And it has a kind of very orange glow.

- [Narrator] The Say's firefly is Indiana's official state insect.

We travel now to West Lafayette where the concern of a student and her teacher made it all happen.

- Well, I always believed in the teachable moment.

And when Kayla borrowed, you know, one of my books it was a guide to the 50 states.

And she came back two days later and said, as a seven year old, very soft spoken young lady, "We have a problem."

And I was taken aback.

- It appeared that a lot of other states, a vast majority, they had their own state insects.

So out of curiosity, I asked, "What would it take to create a state insect for Indiana?"

So then that kind of spurred on this project that would span four years.

A lot of work, a lot of letters, postcards, petitions, signatures.

- We persevered.

That's what the kids wanted to do each year.

No, we don't wanna give up.

- At the time I was more excited to skip school.

But talking to legislators was good.

We finally got to our governor.

- He was very interested in the letter that my students wrote to him with all the facts they had researched and vetted with the Purdue entomologists.

And he wanted to come up and meet the Firefly Kids as he called them.

- It's official.

(crowd cheering) - And when I see fireflies around I get excited that I was able to achieve that these little bugs are representing Indiana.

The logic behind the Say's firefly is that it was discovered by Thomas Say, someone who lived in New Harmony, Indiana.

- [Narrator] Thomas Say, the father of descriptive entomology in the US moved to New Harmony, Indiana in the 1800s, which was an educational mecca for scientists and lived the rest of his life there.

We traveled to this historic small town to discover a full on Firefly Festival.

- Fireflies in New Harmony ♪ And the fireflies flicker ♪ - [Narrator] Complete with lightning bug lectures, firefly drinks.

♪ The fireflies flicker ♪ - [Narrator] Glow-worm dances - Fireflies.

- [Narrator] And a tour into the woods to see what they call natural fireworks.

(cheerful guitar music) ♪ And the fireflies flickers ♪ - [Narrator] Thomas Say is no longer with us but what about his namesake insect?

How are they doing these days?

- In the early 19th century, it was considered to be one of the most common fireflies.

Now as I look for it now, I rarely find it.

For some time they are so rare, I thought they were gone.

The flashing fireflies like to live in darkness.

Of course there's different stages to the night, we all know that.

There's a golden hour and then there's like a twilight and then it gets proper dark and fireflies know that as well.

They've evolved for those different slots of different nighttime.

So depending on light pollution in the area, they might not be there altogether.

The state firefly has sadly that potential that we might have overlooked its demise.

It was considered common.

It's clearly not common now.

And if we continue to treat environment the way we are we might lose the state insect in its home state altogether.

♪ The fireflies flicker ♪ - [Narrator] As it turns out, I had the right flash pattern.

After all, that girlfriend married me and we are back home again in firefly country.

However, due to habitat loss, toxic chemicals and light pollution, there are fewer fireflies now than in the past.

So the next time you see one make a wish upon their star that the children of the future will always dance to their silent love songs.

(indistinct chatters) (audience clapping) - Alright, have yourself a good firefly tour.

- [Narrator] For more stories, go to wfyi.org/acrossindiana.

- [Announcer] This story was made possible by a grant from WETA Presenting Iconic America, Our Symbols and Stories available on the PBS app.